ESXi hosts out of sync on a vDS after migration/upgrade

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

• In vCenter > Networking > vDS > Summary, you see the warning: 
  
  "The vSphere Distributed Switch configuration on some hosts differed from that of the vCenter Server."
  
  
• ESXi log File Path: /var/run/log/
  
  In hostd.log, you see "file not accessible" messages ("skip saving dvport" is not important by itself): 
  
  warning hostd[2100489] [Originator@6876 sub=Hostsvc.NetworkProvider opID=########-#### user=vpxuser] Skip saving dvport ######### to /vmfs/volumes/#####-########-####-##########/.dvsData/## ## ## ## ## ## ## ##-## ## ## ## ## ## ## ##/<port_ID>: file not accessible

• Entries like this can appear if the host's proxy copy loses synchronization with the vCenter, which is, by definition, an "out of sync" condition.

• Some VMs may lose connectivity after being migrated from a host with a cswitch (6.6) proxy vDS to a host with an etherswitch (6.5 and below) proxy vDS.

Environment

• VMware vCenter Server 8.x
  
  
• VMware ESXi 8.x

Cause

• There are many possible causes for these symptoms. 

Resolution

Regardless of other symptoms, if the message "The vSphere Distributed Switch configuration on some hosts differed from that of the vCenter Server" is seen in the vCenter Networking icon view, Summary tab of a vDS, then follow the steps on the following KB --> KB 412915 - "The vSphere Distributed Switch configuration on some hosts differed from that of the vCenter Server" seen in the vCenter Networking icon view, Summary tab of a vDS